Simulation of microstrip small antennas

Microstrip patch antennas are being increasingly used in communication and radar systems because they have many advantages over conventional antennas, such as being lightweight, compact and conformal. There has been increased interest in minimising microstrip patch antennas for some specific applications, such as mobile communications and monolithic microwave integrated circuits. There are a number of approaches to reduce the size of patch antennas. In this paper, a meander slot antenna and a meander line antenna were investigated using a 3-D FDTD simulator and a microwave network analyser. The meander slot antenna is a single layer structure fed by an open-end of a stripline whereas the meander line antenna is a multilayer structure fed by an open-end of a microstrip. The basic principle of these meander antennas is developed and illustrated through a transmission line theory and simulated electric and magnetic field distributions in the meander slot or line. The return loss, resonant frequency, bandwidth, radiation patterns and radiation efficiency of these meander antennas with various meander sections have been presented and compared with measured results. The agreements between the simulated and measured results are good.